Wheel for a motor vehicle

ABSTRACT

The wheel (W) includes an outer rim ( 1 ), made of a metal material, for supporting a tyre; first and second annular elements ( 2, 3 ), also metal, are each arranged within the rim with a circumferential skirt ( 10, 11 ) adjacent the rim ( 1 ) and a perimetral edge ( 10   a   , 11   a ) connected to a corresponding outer edge ( 8   a   , 9   a ) of the rim ( 1 ), with an inner annular flange ( 12, 13 ) lying in a plane substantially orthogonal to the axis (A-A) of the wheel (W) and facing and fixed to a corresponding flange ( 13, 12 ) on the other annular element ( 3, 2 ) so as to form an annular assembly ( 15 ) for fixing to a wheel hub; and stiffening means ( 18; 22, 23 ) provided in the region ( 17 ) defined between the rim ( 1 ) and the circumferential skirts ( 10, 11 ) of the said annular elements ( 2, 3 ).

[0001] The present invention relates to a wheel for motor vehicles in general.

[0002] More specifically, the object of the invention is a wheel for a motor vehicle which includes a metal outer rim for supporting a tyre

[0003] The motor vehicle wheel of the invention is characterised in that it also includes

[0004] first and second annular elements, also both made of metal and each arranged within the rim and having a circumferential skirt adjacent the rim, with an edge connected to a corresponding edge of, the rim, and an inner annular flange lying in a plane substantially orthogonal to the axis of the wheel and facing and fixed to a corresponding flange on the other anular element so as to form an annular assembly for fixing to a wheel hub, and

[0005] stiffening means provided in the region between the rim and the circumferential claddings of the said annular elements.

[0006] According to a further characteristic, a metal spacer ring is positioned between the flanges of the said -annular elements.

[0007] According to a first aspect of the invention, the aforesaid stiffening means include a heat resistant plastics material, a high-density polyurethane resin for example, injected into this region.

[0008] As well as, or as an alternative to, this plastics material, the stiffening means may also includes at least a pair of shaped metal rings, interposed between the rim and the circumferential claddings of the said annular elements.

[0009] Further characteristics and advantages of the invention will become apparent from the detailed description which follows, provided purely by way of non-limitative example, with reference to the appended drawings, in which:

[0010]FIG. 1 is an axially sectioned partial view of a motor vehicle wheel of the invention, and

[0011]FIG. 2 is an axially sectioned partial view of a variant of the invention.

[0012] A wheel according to the invention is generally indicated W in FIG. 1.

[0013] This wheel includes a metal-outer rim 1. Using methods known in the art, this wheel is made from a sheet of metal, in particular steel, bent into a ring. The ends of the sheet are welded together and the ring thus constructed is formed into the desired shape by forming and rolling operations.

[0014] In the embodiment shown by way of example, the wheel W is a wheel for a commercial vehicle and the rim 1 has a central portion 4 which is depressed, forming a channel between two circumferential humps 5. The humps 5 separate the channel portion 4 from two shoulder portions 6 and 7, an outer and an inner shoulder respectively, which are provided to receive the beads of a tyre (not illustrated).

[0015] The shoulder portions 6 and 7 are connected to curved edge portions 8 and 9 of the rim, which are outwardly convex.

[0016] The shape of the rim shown in the drawings is not limitative however.

[0017] The wheel W also comprises two annular elements 2 and 3, also both made of metal, arranged within the rim 1. These annular elements 2 and 3 are made by cutting and drawing, for example, and each have a circumferential skirt 10, 11 adjacent the rim 1 and having a perimeter edge 10, 11 a joined, by a folded seam for example, to a corresponding outer edge 8 a, 9 a of the rim 1.

[0018] Alternatively, the edges 10 a, 11 a of the annular elements 2 and 3 could be fixed to the edges 8 a and 9 a of the rim 1 by welding, TIG welding for example.

[0019] The annular elements 2 and 3 also each have an inner flange 12, 13 lying in a plane substantially orthogonal to the axis A-A of the wheel W and each facing and fixed to a corresponding flange 13, 12 of the other annular element. A metal spacer ring 14, made of steel for example, is preferably interposed between the flanges 12 and 13 of the annular elements 2 and 3.

[0020] Conveniently, the flanges 12 and 13 of the annular elements 2 and 3 are fixed to each other and to the spacer ring 14 by welding, projection welding for example.

[0021] The flanges 12, 13 and the spacer ring 14 form together an annular assembly 15 for fixing to a wheel hub (not illustrated). To this end, it is convenient for the assembly 15 to have openings or through-holes 16 for fixing means such as bolts or the like.

[0022] In the structure as described, a region 17 is defined between the rim I and the circumferential skirts 10 and 11 of the annular elements 2 and 3.

[0023] In order to stiffen the structure of the wheel W, a heat resistant plastics material 18, such as a low-expansion or high density polyurethane resin, can be injected into the region 17. This plastics material can be injected through one or more of the holes formed in at least one of the annular elements 2 or 3, such as the opening indicated 19 in FIG. 1.

[0024] A valve 20 for inflating the tyre can be fitted into a passage 21 formed through the outer portion of the rim 1 and also through the skirt 10 of the annular element 2, as well as through the stiffening plastics material 18, as shown in FIG. 1.

[0025]FIG. 2 illustrates a variant of the wheel according to the invention.

[0026] In this drawing, parts and elements which have already been described have been given the same reference letters or numbers.

[0027] In the variant of FIG. 2, two metal rings 22 and 23 are provided in the region 17 defined between the rim 1 and the annular elements 2 and 3 as additional means for stiffening the structure of the wheel. In the embodiment illustrated, the metal rings 22 and 23 form a channel in cross section, with the concavity facing the rim 1, and are arranged at the humps 5 in the region 17. The upper edges 22 a, 23 a respectively of these rings are folded over in contact with the inner surface of the rim 1 and, more conveniently, are welded thereto. The bottom surface of the channel-like portion of the stiffening rings 22 and 23 are each welded to a corresponding portion of the skirts 10 and 11 of the annular elements 2 and 3.

[0028] In a further variant, which is not illustrated, a wheel according to the invention may be constructed as in FIG. 2 but without the plastics material 18 in the region 17. In this case, only the stiffening rings 22 and 23 reinforce the wheel structure.

[0029] The motor vehicle wheel of the invention can easily be constructed in such a way that it weighs the same as an equivalent conventional wheel made of a light metal alloy such as an aluminium alloy and significantly less than a conventional pressed steel wheel.

[0030] On the other hand, the manufacturing cost of the wheel of the invention is similar to that of a conventional pressed steel wheel and significantly less than that of a light alloy wheel. These characteristics make the wheel of the invention particularly advantageous.

[0031] Naturally, the principle of the invention remaining unchanged, embodiments and manufacturing details may vary widely from those described and illustrated purely by way of non-limitative example, without departing thereby from the scope of the invention as claimed in the appended Claims. 

1. A wheel (W) for a motor vehicle including an outer rim (1) of metal material for supporting a tyre; first and second annular elements (2, 3), also of metal material and each arranged within the rim (1) with a circumferential skirt (10, 11) adjacent the rim (1), each with a perimetral edge (10 a, 11 a) connected to a corresponding edge (8 a, 9 a) of the rim (1) and an annular inner flange (12, 13) lying in a plane substantially orthogonal to the axis (A-A) of the wheel (w) and each connected to a corresponding flange (13, 12) of the other annular element (3, 2) so as to form an annular element (15) for fixing to a wheel hub; and stiffening means (18, 22, 23) arranged in the region (17) defined between the rim (1) and the circumferential skirts (10, 11) of the said annular elements (2, 3); said stiffening means including a heat resistant plastics material (18) injected into the aforesaid region (17); characterised in that the said stiffening means include a pair of metal rings (22, 23) interposed between the rim (1) and the circumferential skirts (10, 11) of the said annular elements (2, 3), circumferential humps (5) being formed in the edge portions of the rim (1) and the said metal stiffening rings (22, 23) being provided in the aforesaid region (17) at the site of the humps (5).
 2. A wheel according to claim 1, in which a spacer ring (14) made of a metal material is interposed between the flanges (12, 13) of the said annular elements (2, 3).
 3. A wheel according to claim 1, in which the said plastics material is a high-density polyurethane resin.
 4. A wheel according to claim 1, in which the said stiffening rings (22, 23) form a channel in cross section with the concavity facing the rim (1).
 5. A wheel according to claim 1, in which the said annular elements (2, 3) and the rim (1) are joined to each other by a folded seam along their juxtaposed edges (10 a, 11 a; 8 a, 9 a).
 6. A wheel according to claim 1, in which the said annular elements (2, 3) are connected to the rim (1) by welding.
 7. A wheel according to claim 2, in which the flanges (12, 13) of the said annular elements (2, 3) are fixed together and to the spacer ring (14) by projection welding.
 8. A wheel according to claim 2, in which openings (16) are formed through the said flanges (12, 13) of the annular elements (2, 3) and through the interposed spacer ring (14) for passage of fixing members for fixing the wheel (W) to a wheel hub. 